PHP · Theory

vprintf()

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Theory

274/352

vprintf()

Sara only reaches for vprintf() when Hello, Asha has to stay correct in a web page.

Do vprintf() once by hand. echo / print. Change one input. Say the new result out loud.

Skip vprintf() and missing semicolon shows up in a web page.

vprintf() shows up in a web page. Name Hello, Asha, not “a real-world scenario”.

Don’t do this with vprintf() — missing semicolon. Interviewers spot it in ten seconds.

After vprintf(), Sara should still remember missing semicolon.

Viva for vprintf() — what it is → echo / print → the mistake (missing semicolon).

Exam tip

For vprintf(): definition + a web page + one failure.

Example

<?php
// vprintf()
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

vprintf(): scores array, print avg, then high marks. Say the output.

Short notes

Defvprintf() — Sara uses it for Hello, Asha in a web page.
Rulevprintf() → echo / print.
Remembervprintf() + the PHP runtime (a web page).
Usevprintf() in a web page (Hello, Asha).
Trapvprintf() — missing semicolon.
Exvprintf() → Hello, Asha.

PHP · Theory

vprintf()

← All stacks

Theory

274/352

vprintf()

Sara only reaches for vprintf() when Hello, Asha has to stay correct in a web page.

Do vprintf() once by hand. echo / print. Change one input. Say the new result out loud.

Skip vprintf() and missing semicolon shows up in a web page.

vprintf() shows up in a web page. Name Hello, Asha, not “a real-world scenario”.

Don’t do this with vprintf() — missing semicolon. Interviewers spot it in ten seconds.

After vprintf(), Sara should still remember missing semicolon.

Viva for vprintf() — what it is → echo / print → the mistake (missing semicolon).

Exam tip

For vprintf(): definition + a web page + one failure.

Example

<?php
// vprintf()
$scores = [80, 90, 70];
$avg = array_sum($scores) / count($scores);
echo "avg=" . number_format($avg, 1) . "\n";
foreach ($scores as $s) {
  if ($s >= 80) echo "high: $s\n";
}

vprintf(): scores array, print avg, then high marks. Say the output.

Short notes

Defvprintf() — Sara uses it for Hello, Asha in a web page.
Rulevprintf() → echo / print.
Remembervprintf() + the PHP runtime (a web page).
Usevprintf() in a web page (Hello, Asha).
Trapvprintf() — missing semicolon.
Exvprintf() → Hello, Asha.

vprintf()

Example

Short notes

Questions

vprintf()

Example

Short notes

Questions